It is possible to go over the bars with almost any brake. I'm confident that isn't going to happen, been doing this too long. Remember when V brakes first came out? You had a lot of people saying "too powerful, can go OTB" and then the same when dual pivot came out.

The front wheel doesn't completely stop moving over heavy braking. It is just moving more slowly than the rest of the bike, hence the rear lifting.

In any case, in determining the ratio of level force to braking force, the ratio of rotor radius to wheel radius (by simple Newtonian mechanics - think two levers fighting each other) matters more than absolute rotor size. For the same braking force, 700c wheels should have larger rotors than 26" wheels.

And the difference isn't huge. Less than the difference being in the tops or the drops. you don't hear anyone say "Don't ride in the drops or you'll do an endo if you brake".